Why does asparagus make urine smell? Are there any other vegetables that have a similar effect?

Bob Adams, Birmingham UK

Asparagus contains a sulphurous compound called mercaptan (which is also found in rotten eggs, onions and garlic). When your digestive system breaks down mercaptan, by-products are released that cause the strange smell. The process is so quick that your urine can develop the distinctive smell within 15 to 30 minutes of eating asparagus.
Not everyone suffers this effect; your genetic makeup may determine whether your urine has the odour -- or whether you can actually smell it. Only some people appear to have the gene for the enzyme that breaks down mercaptan into its more pungent parts.

I am reliably imformed by a female friend that beetroot makes semen taste pleasant. Not quite the same, but a similar effect.

The Cornish Deity, Lamorna, Cornwall

I have been the sole witness to the experience of my urine turning red when I had eaten beetroot. Fortunately I was forewarned, otherwise I probably would have freaked!

Maureen , UK

I don't know about vegetables. But sugar pops cereal make the urine smell pleasantly malty!

Robert Case, Chicago, IL USA

I think it's something to do with the body getting rid of waste or uneeded substances, which is one of the major reasons why we urinate (eg. disposal of urea from the blood to the bladder via the kidneys). Sugar is so highly concentrated in such cereals as described above that the body quickly turns it to solution and sends it onwards to the bladder. With beetrooot, it is the naturally present red colouring which is not required and so becomes a waste product and effectively 'dying' the urine. A common test for kidney damage is for doctor to inject a dye into the bloodstream which can show up on certain types of X-rays as it flows around the body. This dye is harmless and eventually leaves the body via urination and also can 'dye' the urine a different colour.

Spyder Webb, Liverpool England

Puffed wheat affects me - but my wife claims that it has no effect on her. I wonder if this is more often noticed by men than women?

Francis McLoughlin, Milton Keynes UK

Pretty much anything and everything you eat affects the smell of your urine and bowell movements... it's just a matter of big differences and ones that we can't notice. On that same note, what you eat also affects your secretions. It is said that people who eat a lot of naturally sweet foods, like berries, "taste" sweeter.
Back to the pee, though, I've found that after eating tofurkey, my pee smells exactly like the tofurkey... (which smells like turkey).

Melissa, Walled Lake, Michigan

Regarding beetroot making semen taste strange, so does asparugus. Fear not though I have been reliably informed by both gay and straight male friends pineapple has the opposite effect and it happens very quickly!

Sharon, london UK

I feel from many test that this is not true! We have tried this a few times and it failed everytime. In reality, it make it taste worst. CAUTION DO NOT TRY THIS!!!!!

Beatrice, Little Rock, USA

My Husband and i have just started to eat Asparagus as they say it is very good for you, and we have both had a giggle because when we went to the loo, we could'nt believe how strong the smell of our urine was, we both said it smelt like Barbecue food. But we still continue to eat Asparagus as it tastes lovely.

Anna, Ashford Kent

I have also noticed that if you have a lot of coffee, this also makes urine smell exactly like Sugar Puffs. What's the connection?

Peter F, Sydney, Australia

I eat asparagus on the regular and love every last piece. It does make my pee smell really powerful and weird. I started to use the urinal and some guy walked up and started to do his thing next to me. He had to have been like "what the hell is that", he probably thought it was him!! Funny, I almost laughed out loud. They say in almost everything I have read that only 40 percent of people`s pee will smell. I also smell it in my sweat.

Clifton Maxson, Jacksonville, Florida, USA

I have also read that some people cannot smell the sulphurous fumes of asparagus-laced urine! So even if asparagus DID affect their urine, they wouldn't know!
This might be of some comfort to Clifton!

Tilly Trelawney, Bodmin, Cornwall UK

I also find coffee makes my wee smell of sugar puffs.

Helen, Nottingham, England

Hi, I am in the 4th grade, and I am doing my Science Fair project on, "Does Asparagus make your pee smell?" I am so excited, I am going to test all ages and compare them male vs female.

Hunter Jordan, Bossier, USA

I had asparagus for dinner the other night and shortly after I had to go pee. When I started to pee I began to smell this very bad odor,I mean bad too, I was like this smell can't be coming from me but sure enough it was my urine. I didn't know why untill I shared it withan uncle of mine he then told me that aparagus does make your pee stinky.

Alex Gomez, Fillmore, California, USA

I find that eating asparagus gives me painful ears and a sore throat. Has anyone else had this reaction?

Howard Bailey, Preston

If you're having side effects like a sore throat or your ears hurt it could mean you're allergic to asparagus.

Chardy Wolfe, Parma, Ohio, USA

I've noticed the asparagus smell before but tonight I had it for dinner, went to the loo literally ten mins after I'd eaten and it stank! Never realised it could react that fast! Weird!!

Lindsay Abbas, Lincoln, Lincolnshire, UK

I eat a children's "breakfast cereal" crudely named Weetos on a daily basis as it makes my ordure reek of sweet Swiss chocolate.

Parson Major, Tunbridge Wells, UK

I'm with the tofurkey. Within about half an hour of eating it, my pee smells like tofurkey.

Kevin, Edmonton Canada

Glad I looked on the web before I went to the doctor.I ate asparagus and that evening I thought I had a urine infection.
The smell was of strong sulphur
I also react to onions & if I eat garlic I can smell it in my sweat. I guess I have the gene.
Does anyone know which gene this is?

Freda, Blackburn, UK

I do have the strange and sweet urine smell after I eat asparagus. For a long time I identified this smell as diabetic urine. I was truly happy when I found out it was simply the asparagus that causes the sugary smell (but after 3 days, the smell is more like pure sugar). I wonder if eating asparagus is bad for the pancreas?

Christiane Guignard, RN, Havana, Florida, USA

It's asparagus season - so I was curious about the distinct smell when pee-ing having eaten asparagus. There's a lot to read - and interesting that not all asparagus eaters have smelly pee, and only a proportion can actually smell it. Btw, my pee also reminds me whenever I've had Sugar Puffs/Puffed Wheat for breakfast!

John Gimson, Bude, Cornwall England

Within ten minutes of eating asparagus the worst odour is produced when I urine. I thought something was wrong with me. I didn't realize it was from the vegetable. I was frightened because my urine smelled very strong for 3 days. I might have to give up the green stalks because the smell isn't worth it.

Fiona, San Diego, US

I'm female and fish (especially haddock), green veggies and puffed wheat cereals are worse for me. The urine is very strong and sometimes embarrassing. I love these foods and I know they are good for me so don't want to avoid them!

Trish Campbell, Coventry UK

It's not to do with genes... About half the population experience strange smelling (and sometimes green!) urine after eating asparagus  this is due to sulphur-containing amino acids in the veg that break down during digestion. Different people form different amounts of these compounds after eating asparagus, and many people cannot smell the odour even when they produce the compounds.

Ruby, Ipswich UK

Why do you lot think it is necessary to discuss you toilet habits?!!

Phil, Canterbury Uk

If I drink cider it makes my wee smell quite peculiar. I also thought I had a urine infection the first time this happened.

Howard Brown, Bridgnorth Shropshire

To see it worked into a sentence with the word semen certainly explains how "beetroot" got its name.

I. P. Daily, Hobbit on the Cistern Wales

I've noticed after eating asparagus that my pee is bright yellowish green. B12 vitamin supplements seem to have the same effect and I wonder if it's the same cause.

Jennifer Macdonald, London, Ontario Canada

I love fish and I eat enormous amounts of it. After eating some fish eg herring seabass or catfish pee stinks to high heaven but after eating others - trout salmon and hallibutt for example it doesn't! Why is this (no one seems to know this)

lieecy, bolton uk

On a similar note, I find that when I eat spicy food my urine feels very hot. I like chili and make it very hot, but within half an hour my wee feels like molten lava! If I don't urinate then I feel the heat building up in my bladder.
Curiously this phenomenon has replaced the more customary 'ring of fire' most people experience after spicy food. I used to get a hot bottom but around five years ago (in my early 30s) this was replaced by lava-wee.

Simon Brown, Southsea, United Kingdom

I discovered a great way to get my nephews to eat their veggies.
At a recent family dinner, asparagus was served. Of course, the boys didn't want to eat it.
When I told them that eating asparagus would make their pee smell like a skunk, they were all like, "No way!" I said, "Yes! Way!" Their father, who was a medical student, chimed in and confirmed.
The two boys said, "Cool!" and their plates were clean in mere minutes.
Now they can't get enough "skunk weed."
(Methyl mercaptan is one of the chemical constituents of the skunk's musk.)

Randy S., Erie, PA USA

With me it is BBQ chips lol within 10 to 15 min. I can smell the spices very strong. Very strange, doesn't happen with anything else I know of.

Andrea, Toronto, Canada

I once ate Asparagus and pissed myself, and everyone noticed, and said err, you smell like Asparagus piss. I must have the gene, fascinating!!

Marcus DiMaro, Lincoln UK

I've thought for a long time that 'Asparagus P' would make a great name for a rapper.

Ed, Perth Australia

Asparagus makes my urine smell very rapidly, and I think it is like brasso (metal polish)- bit odd really....

Jonathan, Billesdon Uk

I tried asparagus for the first time recently and Im 51 years old. Yes, it has a peculiar, yet unpleasant odor, kinda like when my maltese terrier peed on the floor. I saute mine in butter and season it to taste. I just started changing my diet because I'm trying to lose weight & this was recommended but I've broken out in this horrid BODY RASH like heat bumps and I dont know if its the asparagus, the hot sun, my uniform is polyester, or its simply my high stress level. Which brings me to comment on this: I have 28 food allergies, all healthy foods and I have 15 or so allergens to environmental, dust, perfumes, sprays, cigarettes(smoke), animals, chicken/eggs, dairy, I'm lactose, I have vitaligo since 2009 spreading, the ultraviolet rays burn my skin, I am miserable but you will always see me laugh/smile. Nothing has worked but today Im going to try this epsom salt bath, I cant sit in water cause it dries me terribly and my skin cracks if I dont hurry to moisturize it. Sad huh? yep

Lina, las vegas usa`

I ate a large bunch of asparagus last night with my dinner and my urine smelt very strong until about 1pm today, so it took about 18 hours to go through fully. It was also a dark colour. I haven't noticed it before when having eaten asparagus but yesterday, I had a particularly large bunch. Greedy me!
When I've been drinking ground coffee, I smell that in my urine too.

Portia, Manchester United Kingdom

the gene only determines if you can smell it, but it makes everyone's pee smell but only about 40% of people can smell it.

cj, d town us

Not everyone has the gene that breaks down the mercalstan in asparegus that gives that skunk smell in our urine. It lasts two days with me.

mimi taylor, cambridge,ma. usa

Re the bit about your body getting rid of excess sugar in breakfast cereals through urination, this would only happen if you suffered from diabetes. In the non-diabetic person, all of the sugar, no matter how much you take in, is retained by the body (it's still in caveman mode and doesn't know when it's going to get fed again!). This is why taking excess sugar makes you put on weight as the excess is converted into glycogen or fat.

sandy laird, Edinburgh

Related to this discussion - I had a great job as a student picking asparagus. £10 an hour plus tips!
PS: I love asparagus and make sure I pee in privacy afterwards.

David, Poole UK

I have a list. Asparagus, sugar puffs, some fish and corned beef.

pam, liverpool england

Some humans can smell it but some can't all humans make the smell I can't smell it but my wife can smell my urine.

John Smith, New York City USA

Asparagus also high in antioxidants and boiling it and drinking it as a tea placed in the fridge shortly after with pomegranate or cranberry helps women fight fibroids if drunk twice daily for five to six months. It will drink fibroids naturally.

Charlotte Gonzales, Georgia USA

i am weird. i quite like the smell after i have eaten asparagus

john, erith UK

On a similar note, I have noticed that my pee smells really bad after having local anesthetics at the dentist (injection). It's a similar bad odor to when I eat asparagus. Maybe it's all related?